Supporting member and supporting member assembly for implantation into or between subjects bones, and template plug and tamper corresponding to the same

ABSTRACT

The present invention provides a supporting member and a supporting member assembly including the same to be implanted into or between a subject&#39;s bones, and a template plug and a tamper corresponding to the supporting member. The supporting member comprises a main body; a first connecting portion and a second connecting portion formed on the upper and lower sides of the main body respectively and forming a dovetail joint with each other; and a guiding structure formed at a side of the main body and including guiding holes as well as a buffer groove for mating with an external template plug. The supporting members of the invention can be sequentially implanted and connected into a bone or between two connected bones, and improve the defect of the conventional one-size giant implants injuring the surrounding nerves.

BACKGROUND OF THE INVENTION 1. Technical Field

The present invention relates to a supporting member and a supportingmember assembly to be implanted into or between a subject's bones, and atemplate plug and a tamper corresponding to the supporting member. Moreparticularly, the invention relates to a supporting member that can beconnected with at least one supporting member of the same structure asits own in a bone or between two connected bones, a supporting memberassembly composed of such supporting members, and a template plug and atamper corresponding to such supporting members.

2. Description of Related Art

The societies many of us live in are aging or aged, which raisesconcerns about health issues of the elderly. A senior citizen tends tosuffer from osteoporosis and is therefore prone to bone fractures oreven vertebral compression fractures. While vertebral compressionfractures in most patients can heal within months, the recovery periodis anything but easy. For example, persistent pain in the lower back ornerve compression may inconvenience a patient's daily life to such anextent that the patient ends up bedridden, whose complications includebedsores, pneumonia, and urinary infection, among others. Some patients'vertebral compression fractures do not heal at all and hence give riseto permanent pain, if not compromising the stability of the entirevertebral column or leading to a hunchback, in the latter case of whichthe vertebrae adjacent to the fractured one(s) may suffer fromcompression fracture too, as in a domino effect. Besides, patients withsuch related diseases as degenerative disc disease, herniation ofintervertebral disc, spondylolisthesis, spondylolysis, spinal canalstenosis, or pseudoarthrosis may experience back pain, sciatica,claudication, or weakness in the legs.

Treatment for vertebral compression fracture can be carried out in manyways. “Open posterior spinal fixation” and “bone fusion surgery” involvedriving pedicle screws into fractured vertebrae in order to secure andsupport the vertebrae. “Minimally invasive percutaneous vertebroplasty”is an X-ray image-guided procedure in which a bone puncture needleinjects bone cement into a collapsed fractured vertebra through a tinyincision and a pedicle of the vertebra in order to fill the vertebrawith bone cement and thereby relieve pain, but this procedure cannotcorrect a deformed vertebra. “Minimally invasive percutaneous balloonkyphoplasty” uses an inflatable balloon to restore the height of acollapsed vertebra and, after removal of the balloon, injects bonecement into the cavity formed by the inflated balloon in order tocorrect the deformation of the collapsed vertebra to a certain degree.This procedure, however, is not very effective in correcting a deformedvertebra and requires bone cement, too. Other treatments includeimplanting a high-precision medical device (e.g., one designed on themechanical principle of a jack or tripod) into a fractured vertebra forsupport, and yet such medical devices are disadvantaged by theircomplicated mechanical structures, limited supporting effect, and thenecessity of filling with bone cement on a supplementary basis.

Another method for treating a vertebral compression fracture entailsplacing an implant into the fractured vertebra. However, an overly largeimplant may rupture the pedicle through which it passes duringimplantation, causing damage to the nearby nerves, and an implant thatis not large enough for the intended collapsed vertebra can only expandthe vertebra to a limited extent and therefore fails to support thevertebra adequately.

As to treatment between a subject's bones, or interosseous treatment, itis common practice nowadays to incorporate “intervertebral fusion” with“posterior spinal instrumentation” to enhance the effect of rigidfixation.

Intervertebral fusion can be divided by its approach into: anteriorlumbar interbody fusion (ALIF), lateral/oblique lumbar interbody fusion(LLIF/OLIF), and posterolateral/transforaminal lumbar interbody fusion(PLIF/TLIF). ALIF is the golden rule in the art, allowing the largestpossible support element to be implanted, but is disadvantageous in thatit is performed by way of the abdominal cavity, requires a relativelylarge incision, and may injure the intestinal tract, the abdominalaorta, or the ureters, if not resulting in hernia or retrogradeejaculation at the same time. Technically, therefore, ALIF is highlydemanding on both orthopedic and neurological surgeons. LLIF/OLIFreduces the disadvantages of ALIF but necessitates special equipment.PLIF/TLIF is clinically the most widely used, and yet the limited windowattributable to obstruction by the spinal cord and the spinal nervesmakes it difficult to use an adequately sized support element.

Currently, intervertebral fusion can be assisted by placing an implantbetween the vertebrae to be fused. However, an exceedingly large implantmay injure the surrounding nerves, blood vessels, or other importanttissues during implantation, and an implant whose size is smaller thanrequired may result in overly small areas of contact with the adjacentvertebrae, causing problems associated with undue concentration ofpressure.

BRIEF SUMMARY OF THE INVENTION

With regard to implantation into a subject's bones, the conventionalopen posterior spinal fixation and bone fusion procedure when performedon a patient with osteoporosis may require a relatively large incisionand use a relatively large number of screws to secure a relatively largenumber of vertebrae in order to prevent the screws from getting loose.Nevertheless, an extensive spinal fixation operation not only istime-consuming and prone to massive blood loss, but also may lead to thedevelopment of multiple complications (e.g., stiffness in the back,cardiopulmonary failure, and infection) in elderly patients. As tominimally invasive percutaneous vertebroplasty or kyphoplasty, the bonecement used in the operation may leak from the vertebra(e) in question,and a serious leak into blood vessels may result in arterial thrombosis,venous thrombosis, or stroke. If a lot of bone cement leaks to thespinal cord or the nerve roots and subsequently cures (the curingprocess generates high heat), the surrounding nerves will be severelycompressed and damaged. Moreover, when bone cement exists permanently asthe filler in a fractured vertebra, the low bone-compatibility andextremely high hardness of bone cement may give rise to bone resorption,hinder the healing of the fracture, or even fracture a neighboringvertebra.

As for implantation between a subject's bones, the conventional devicesfor intervertebral fusion are the intervertebral cages, which can beroughly divided into those of a unitary structure and those of acomposite structure. Common unitary-structure cages are in the shape ofa disc, straight bullet, or banana and have a simple structural designthat requires the use of a complicated tool during implantation in orderto prevent nerve and blood vessel injuries. Clinically, therefore, aunitary-structure intervertebral cage often falls short of its requireddimensions such that the areas of contact between the cage and theadjacent vertebrae are not large enough to avoid pressure concentration(which may cause subsidence or extrusion of the intervertebral cage intoor from the vertebrae) or promote intervertebral fusion (the failure ofwhich may lead to the formation of a false joint, i.e.,pseudoarthrosis). Composite-structure intervertebral cages eitherincorporate a screw or have an expandable structure. The screw-typecages, though featuring enhanced fixation, add to the difficulty ofsurgical operation and are applicable only in ALIF. Theexpandable-structure intervertebral cages can be further divided intothe medial-lateral expansion type and the caudal-cranial expansion type,both of which enable relatively large areas of contact and increasedfixation but have rather intricate mechanical structures, including, forexample, a large number of articulations and points of stressconcentration. These complex structures not only limit the amount ofbone graft that can be packaged in each cage, but also increase thechances of long-term fatigue failure and false joint formation betweenvertebrae.

As is well known in the art, a bone implant must not be a complicatedmechanical assembly, which tends to fatigue, disintegrate, or fail afterpersistent use in the human body. In addition, a bone implant ispreferably highly bone-compatible or even conducive to the healing ofbone fracture and therefore must not include materials that are rarelyused, or not allowed to be used, in the human body. Regarding thetreatment of bone fracture, therefore, many issues remain to beaddressed by medical experts and scientific researchers.

In view of this, in order to solve the above problems, the primaryobjective of the present invention is to provide a supporting member forimplantation into or between a subject's bones, comprising: a main bodyhaving two opposite sides defined respectively as an upper side and alower side; a first connecting portion formed at the upper side of themain body and shaped as a male or female part of a dovetail joint; asecond connecting portion formed at the lower side of the main body andcorresponding in shape to the first connecting portion; and a guidingstructure formed at a side of the main body and configured to mate withan external template plug; wherein the first connecting portion of thesupporting member is connectable with the second connecting portion ofanother said supporting member to form a said dovetail joint.

In a preferred embodiment, the first connecting portion is a dovetailblock and the second connecting portion is a dovetail groove in order toprevent two vertically connected said supporting members from separatingfrom each other after connecting in a sliding manner.

In a preferred embodiment, a front side of the first connecting portionfurther includes a first positioning portion, a front side of the secondconnecting portion further includes a second positioning portion, andthe second positioning portion corresponds in shape and position to thefirst positioning portion; wherein, the first positioning portion is apositioning block and the second positioning portion is a positioninghole so that the supporting members with such structures are able toposition and fasten to each other.

In a preferred embodiment, a front side of the main body has a U-shapedgroove structure that can be compressed or deformed to facilitatefastening between supporting members and return to an original shapeelastically to prevent the supporting members from separating from eachother.

In a preferred embodiment, the guiding structure includes a plurality ofguiding holes and/or buffer grooves.

In a preferred embodiment, the guiding holes and the buffer grooves havevarious designs with progressive deviation or difference in terms ofangle, position, size, or shape.

In a preferred embodiment, the main body is one or a plurality ofreticulated structures.

In a preferred embodiment, the reticulated structure can be filled witha bone-filling material or bone cement.

In a preferred embodiment, the bone is a vertebra.

In a preferred embodiment, a material of the supporting member includesmetal, plastic, or a mixture thereof.

Another objective of the present invention is to provide a template plugconfigured to guide the aforementioned supporting member into or betweena subject's bones, which includes a plurality of connecting pins, anextension portion, and a grip portion, wherein the extension portion hasone end connected to the plural connecting pins and an opposite endconnected to the grip portion, and the extension portion and/or the gripportion has: a third connecting portion, which is formed on an upperside of the extension portion and/or the grip portion, and is a dovetailprojection; a fourth connecting portion, which is formed on a lower sideof the extension portion and/or the grip portion, and corresponds to thethird connecting portion; wherein, the plural connecting pins can becorrespondingly engaged with the guiding structure of the supportingmember.

In a preferred embodiment, the template plug further includes aplurality of connecting pins and buffer bases.

In a preferred embodiment, the template plug has two connecting pinsthat correspond in design to but are slightly different from the guidingstructure in terms of angle, position, shape, or size.

In a preferred embodiment, the third connecting portion of the templateplug can correspond to the second connecting portion of the supportingmember and the fourth connecting portion can correspond to the firstconnecting portion of the supporting member so that the template plugcan be pushed along and coupled with the supporting member in a slidingmanner.

Still another objective of the present invention is to provide a tamper,which can correspondingly match the aforementioned supporting member ortemplate plug, the tamper includes a slender shaft and a grip portionconnected to the slender shaft; wherein, an upper side of the slendershaft and/or the grip portion further includes a fifth connectingportion corresponding to the second connecting portion, and a lower sideof the slender shaft and/or the grip portion further includes a sixthconnecting portion corresponding to the first connecting portion.

Yet another objective of the present invention is to provide asupporting member assembly to be implanted into or between a subject'sbones, which includes a plurality of aforementioned supporting members,wherein the first connecting portion of each supporting member forms adovetail joint with the second connecting portion of another saidsupporting member in order to connect the plural supporting memberssequentially.

The present invention has the following advantages:

1. The present invention provides a supporting member that is configuredas a micro-unit and whose small size allows not only implantation into abone or between two connected bones, but also connection with other suchmembers in the bone or between the connected bones so as to form asupporting member assembly, making possible a minimally invasive,small-incision surgical operation.

2. The present invention also provides a tamper for restoring afractured bone and pushing/pressing an implanted supporting member, anda template plug for introducing a supporting member into a bone orbetween two connected bones, connecting the supporting member to apreviously implanted supporting member in a sliding manner, and therebyfastening the two supporting members together vertically, before thetemplate plug is removed from the supporting members.

3. The present invention further provides a supporting member assemblythat is formed by sequentially implanting and connecting a plurality ofsupporting members into a bone or between two connected bones so as topush outward the end plate(s) to be treated and thereby expand thecollapsed fractured bone(s). This supporting member assembly is animprovement over the one-size implants used in the conventionalimplantation techniques on the grounds that an existing one-size implantcannot “be a single micro-unit before implantation into or between asubject's bones and connect with other similar micro-units sequentiallyimplanted into or between the bones to form a larger yet completeblock”. In addition, unlike the traditional one-size implants, thesupporting member assembly of the invention will not rupture theaffected bone structure (e.g., a pedicle) or injure the surroundingnerves (e.g., the spinal cord or spinal nerves), blood vessels (e.g.,the abdominal aorta or the vertebral arteries), or other importanttissues (e.g., the ureters) during implantation, or provide inadequatesupport due to an expediently smaller-than-required size.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIGS. 1 (a) and (b) show perspective views of the supporting memberaccording to embodiment 1 of the present invention.

FIGS. 2 (a) and (b) show perspective views of the supporting memberaccording to embodiment 2 of the present invention.

FIGS. 3 (a) and (b) show perspective views of the supporting memberaccording to embodiment 3 of the present invention.

FIG. 4 is a perspective view of the supporting member according toembodiment 4 of the present invention.

FIG. 5 is a sectional view of the supporting member assembly accordingto a preferred embodiment of the present invention.

FIG. 6 is a perspective view of the supporting member assembly accordingto embodiment 5 of the present invention.

FIG. 7 is a schematic diagram illustrating a preferred embodiment of theimplantation system of the present invention.

FIGS. 8 (a) and (b) show perspective views of the template plugaccording to embodiment 6 of the present invention.

FIGS. 9 (a) and (b) show perspective views of the template plugaccording to embodiment 7 of the present invention.

FIGS. 10 (a) and (b) show perspective views of the tamper according toembodiment 8 of the present invention.

FIG. 11 shows schematic views of an implantation system according to apreferred embodiment of the present invention applied to a vertebra in(a) an axial view and (b) a left side view.

FIG. 12 shows (a) an axial view and (b) a left side view of a supportingmember assembly according to a preferred embodiment of the presentinvention applied to a vertebra.

FIG. 13 shows (a) an axial view and (b) a left side view of a supportingmember assembly according to a preferred embodiment of the presentinvention applied to a vertebra.

FIG. 14 shows (a) an axial view and (b) a left side view of a supportingmember assembly according to a preferred embodiment of the presentinvention applied between connected vertebrae.

DETAILED DESCRIPTION OF THE INVENTION

The details and technical solution of the present invention arehereunder described with reference to accompanying drawings. Forillustrative sake, the accompanying drawings are not drawn to scale. Theaccompanying drawings and the scale thereof are not restrictive of thepresent invention.

The use of “comprise/include” means not excluding the presence oraddition of one or more other components, steps, operations, and/orelements to the described components, steps, operations, and/orelements. As used herein and in the appended claims, the singular forms“a,” “an,” and “the” include plural referents unless the contextdictates otherwise.

Hereinafter, the present invention will be further described withdetailed descriptions and embodiments. However, it should be understoodthat these embodiments are only used to help understand the inventionmore easily, not to limit the scope of the invention.

The present invention is designed not only for implantation into orbetween human bones, but also for use in other vertebrates such asamphibians, reptiles, birds, and mammals. Furthermore, the invention canbe used in or between any suitable bones, preferably but not limited tovertebrae. In one preferred embodiment, the bone to which the inventionis applied is a vertebra.

Generally speaking, a conventional bone implant cannot be minimallyinvasive and adequately supportive at the same time. To solve theclinical problems associated with bone fracture effectively, the presentinvention aims to provide a supporting member, a supporting memberassembly, a template plug for guiding the supporting member into asubject's bone or between two connected bones, and a tamper forassisting the required implantation operation. A detailed description ofsome embodiments of the invention is given below.

[Embodiments 1 to 4]—Supporting Member

Please refer to FIG. 1 to FIG. 4 for perspective views of foursupporting members 100 according respectively to embodiments 1 to 4 ofthe present invention.

The supporting members 100 according to embodiments 1 to 4 areconfigured to be implanted into or between a subject's bones and eachinclude a main body 11, a first connecting portion 12, a secondconnecting portion 13, and a guiding structure 14. The main body 11 hasan upper side and a lower side, which is the opposite side of the upperside. In embodiment 3, referring to FIG. 3, the main body 11 ispreferably one or a plurality of reticulated structures. This embodimentis advantageous in that the at least one reticulated structure can befilled with a bone-filling material (e.g., bone cement), provides spacefor the proliferation of osteoblasts, allows passage of nutrients,produces a supporting effect similar to that of trabeculae, andfacilitates fusion between the main body of the supporting member (orthe filler therein) and the surrounding ossein, thereby assisting in thehealing of a bone fracture. In embodiment 2, referring to FIG. 2, themain body 11 has one or a plurality of holes (e.g., through holes with adiameter ranging from about 0.3 mm to about 5 mm), wherein the at leastone hole is intended to provide space that can be filled with abone-filling material, promote the proliferation of osteoblasts and thedelivery of nutrients, enhance filler (e.g., bone cement) attachment,and reduce the weight and Young's modulus (also known as the modulus ofelasticity) of the implant.

The first connecting portion 12 is formed on the upper side of the mainbody 11 and is shaped as the male part of a dovetail joint. The secondconnecting portion 13 is formed in the lower side of the main body 11and corresponds in shape to the first connecting portion 12. The firstconnecting portion 12 of a supporting member 100 can be connected to thesecond connecting portion 13 of another supporting member 100 to form adovetail joint. As used herein, the term “male (or female) part of adovetail joint” refers to a trapezoidal structure protruding from (orsunken into) the main body 11, and the term “dovetail joint” refers to ajoint formed by such a protruding trapezoidal structure engaged with,fastened to, connected in a sliding manner to, or otherwise secured in amatching sunken trapezoidal structure. In one preferred embodiment, thefirst connecting portion is a dovetail block, the second connectingportion is a dovetail groove, and the first connecting portion of asupporting member with such connecting portions can form a dovetailjoint with the second connecting portion of another such supportingmember, as shown in FIG. 5. This structural feature aims to prevent twovertically connected supporting members from tilting sideways withrespect to and separating vertically from each other after thetrapezoidal dovetail groove of the upper supporting member is mated, ina sliding manner, to the “top rail” formed by the dovetail block of thelower supporting member; in short, the structural feature is intended tofasten or lock the supporting members together after the supportingmembers are implanted into a bone or between two connected bones. Insome embodiments, the first connecting portion is a dovetail block whosewidth gradually increases from the front end toward the rear end, andthe second connecting portion has a corresponding shape so that whilethe second connecting portion of a supporting member with suchconnecting portions is being mated, in a sliding manner, to the dovetailblock of another such supporting member, the former supporting membercan only be moved forward but not rearward.

In some embodiments, the first connecting portion further includes afirst positioning portion, and the second connecting portion furtherincludes a second positioning portion corresponding in shape andposition to the first positioning portion. For example, the firstpositioning portion may be a protruding structure while the secondpositioning portion is a recessed structure corresponding in shape tothe protruding structure, or the first positioning portion may be arecessed structure while the second positioning portion is a protrudingstructure corresponding in shape to the recessed structure. Theforegoing designs of the positioning portions are advantageous in thatthe first positioning portion and the second positioning portion can befastened to each other to prevent two connected supporting members fromgetting loose with respect to each other. In one preferred embodiment,the first positioning portion is a projection, and the secondpositioning portion is a recess. In embodiment 3 as well as embodiment1, the front side of the first connecting portion 12 of the supportingmember 100 is provided with a terminal positioning bump (i.e., the firstpositioning portion 121), and the bump can enter, in a sliding manner, apositioning hole (i.e., the second positioning portion 131) of the nextimplanted supporting member 100 to prevent the two supporting members100 from sliding with respect to and separating from each other ineither the forward or the rearward direction. In embodiment 4 as well asembodiment 2, the front side of the first connecting portion 12 of thesupporting member 100 is provided with a terminal positioning block(i.e., the first positioning portion 121), and the block can enter, in asliding manner, a positioning groove (i.e., the second positioningportion 131) of the next implanted supporting member 100 to prevent thetwo supporting members 100 from sliding with respect to and separatingfrom each other in either the forward or the rearward direction. In onepreferred embodiment, the main body 11 has a U-shaped groove structure151 as shown in FIG. 2 and FIG. 4 so that when a supporting member withsuch a structure is brought into engagement with another such supportingmember in a sliding manner, and before their positioning portions (e.g.,a positioning bump and a positioning hole) are fastened to each other,the U-shaped groove structures 151 of the two supporting members can beelastically compressed or deformed to facilitate fastening between thepositioning bump and the positioning hole, and that after thepositioning portions are fastened together, the U-shaped groovestructures 151 will return to their original shapes elastically toensure that the positioning bump is securely fastened to the positioninghole to prevent the supporting members from separating from each other.

The guiding structure 14 is formed at one side of the main body 11 andis configured to mate with an external template plug. The guidingstructure 14 may be, for example but not limited to, the guiding holes141 shown in FIG. 1 to FIG. 4. In one preferred embodiment, the guidingstructure 14 includes a plurality of guiding holes (such as but notlimited to two, three, four, or five guiding holes), and there is nolimitation on the shapes of the guiding holes (e.g., the guiding holesmay be circular holes, rectangular holes, triangular holes, otherpolygonal holes, or holes of irregular shapes). In each of embodiments 1to 3, the main body 11 is formed at one side with two guiding holes 141for mating with an external template plug. In embodiment 4, referring toFIG. 4, there are also two guiding holes 141, but the guiding holes 141are connected by a gradually deepened buffer groove 142 that isrelatively wide at a shallow depth and turns pointed as the depthincreases. These two guiding holes 141 and the buffer groove 142 betweenthem are also designed to mate with an external template plug. Theguiding structure 14 aims to connect with the “connecting pins” at thefront end of an external template plug (as detailed further below). Thetwo guiding holes 141 and the buffer groove 142 in embodiment 4 may havevarious designs in terms of angle (e.g., they may diverge or converge inthe forward direction), position (e.g., they may be shifted laterallyoutward or inward with respect to one another), size (e.g., they may betapered in the forward or rearward direction), or shape (e.g., they maybe conical or columnar).

In one preferred embodiment, the material of the supporting member ofthe present invention includes a biocompatible material such as abiocompatible metal, a biocompatible plastic, or a mixture thereof.Suitable metals include but are not limited to magnesium alloys,tantalum alloys (e.g., TaC and TaN), titanium alloys (e.g., GUMMETAL®),nickel-titanium alloys, nickel-titanium-copper alloys, cobalt-chromiumalloys (e.g., Elgiloy®, a non-magnetic cobalt-based hardenablecobalt-chromium-nickel superalloy), cobalt-chromium-nickel alloys (e.g.,Phynox®), chromium-tungsten-nickel alloys (e.g., L605),cobalt-chromium-vanadium alloys, cobalt-nickel-chromium-molybdenumalloys (e.g., MP35N and MP20N), stainless steel (e.g., 316, 316L, and304), and metallic glass. Suitable plastics include polymers,copolymers, composite materials, and mixtures of the above, such as butnot limited to styrene-based elastomers, olefinic elastomers,polyolefinic elastomers, polyurethane-based thermoplastic elastomers,polyamides, polybutadienes, polyisobutylene,poly(styrene-butadiene-styrene), poly(2-chloro-1,3-butadiene),silicones, thermoplastic polyurethanes (TPU), polyurethanes (PU),polysiloxanes (e.g., polydimethylsiloxane (PDMS) and hardpolydimethylsiloxane (h-PDMS)), poly(methyl methacrylate) (PMMA),polyetheretherketone (PEEK), ultra-high-molecular-weight polyethylenes(UHMWPE), and silicon rubber. In a more preferred embodiment, thematerial of the supporting member of the invention includes a titaniumalloy. The foregoing embodiments are advantageous in that a plurality ofsupporting members may, depending on their material properties, besequentially implanted into a bone or between two connected bones,fastened together, and vertically or horizontally stacked until theresulting supporting member assembly has the desired height/width andsupporting strength.

The dimensions of the supporting member of the present invention arepreferably determined according to the size of the space of the targetimplantation site and the size of the incision to be made for theimplantation operation. For example, if the target implantation site isin a vertebra, the supporting member may have a relatively slenderdesign to minimize the hole drilled into the vertebra and therebyprotect the surrounding nerves and blood vessels from injury. That is tosay, the supporting member of the invention can be adjusted and modifiedas needed. The invention imposes no limitation on the dimensions of thesupporting member.

[Embodiment 5]—Supporting Member Assembly

Please refer to FIG. 5 and FIG. 6 respectively for a sectional view anda perspective view of the supporting member assembly 200 according toembodiment 5 of the present invention. The supporting members in thesupporting member assembly 200 are sequentially identified in abottom-up order as the first supporting member 21, the second supportingmember 22, the third supporting member 23, the fourth supporting member24, and the fifth supporting member 25. As the supporting members areimplanted in the same direction, their guiding structures 213 face thesame direction.

The supporting member assembly 200 according to embodiment 5 isconfigured to be implanted into or between a subject's bones andincludes the plural supporting members stated above, with the firstconnecting portion of each supporting member (except for the uppermostsupporting member 25) forming a dovetail joint with the secondconnecting portion of the adjacent supporting member. As shown in FIG.5, the plural supporting members are sequentially connected in such away that the first connecting portion (i.e., the connecting portion 211)of each supporting member (except for the uppermost supporting member25) forms a dovetail joint with the second connecting portion of thenext implanted supporting member. During the process, the firstpositioning portion (i.e., the positioning portion 212) of eachsupporting member (except for the uppermost supporting member 25) isslid into the second positioning portion of the next implantedsupporting member to prevent each two adjacent supporting members fromsliding with respect to each other in the forward or rearward direction.

In one preferred embodiment, the supporting member assembly includes twoto seven supporting members. In a more preferred embodiment, thesupporting member assembly includes three to five supporting members. Inthe embodiment shown in FIG. 5 and FIG. 6, the supporting memberassembly 200 is an assembly of five supporting members, in which, asshown in FIG. 6, the first supporting member 21 and the fifth supportingmember 25 are reticulated structures to provide the space needed for theproliferation of osteoblasts and allow passage of nutrients, and inwhich the second to the fourth supporting members 22, 23 and 24 aresolid structures to be stacked up to increase the height of the spacecreated by the assembly as well as the strength of the assembly, with aview to, for example, pushing two adjacent vertebrae further apart fromeach other vertically. It can also be seen in FIG. 5 and FIG. 6 that thefirst supporting member 21, which only has to connect with the secondsupporting member 22, may have only the first connecting portion, andthat the fifth supporting member 25, which only has to connect with thefourth supporting member 24, may have only the second connectingportion.

A plurality of supporting members of the present invention can befastened together in a modular manner while being implanted into a boneor between two connected bones so as to form a vertical or horizontalstack of the desired height or width and with the desired supportingstrength. The resulting supporting member assembly can push outward theend plate(s) to be treated, thereby expanding a fractured bone orproviding interosseous fixation. The invention allows a plurality ofsupporting members to be connected in the tiny limited space in a boneor between two connected bones in order to stabilize the bone or firmlysecure the connected bones. The number of the supporting membersrequired to be implanted depends on the height of the bone to berestored or the distance between the two connected bones to be secured.Theoretically, the supporting member assembly can be made larger byadding as many supporting members as needed, until the bone to berestored or the space between the two connected bones to be secured iscompletely filled by the assembly. Thus, the invention overcomes theaforementioned drawback of the conventional one-size implants, i.e.,failure to “be a single micro-unit before implantation into or between asubject's bones and connect with other similar micro-units sequentiallyimplanted into or between the bones to form a larger yet completeblock”. The invention also solves such problems of the conventionalone-size implants as the likelihood of their rupturing the affected bonestructure (e.g., a pedicle) or injuring the surrounding nerves (e.g.,the spinal cord or spinal nerves), blood vessels (e.g., the abdominalaorta or the vertebral arteries), or other important tissues (e.g., theureters) during implantation, and of their providing inadequate supportdue to an expediently smaller-than-required size.

To put together a plurality of supporting members of the presentinvention, two template plugs according to the invention can besequentially mated to the guiding structures of the supporting membersin order to guide each supporting member into a subject's bone orbetween two connected bones, connect each two successively implantedsupporting members in a sliding manner, and fasten each two successivelyimplanted supporting members together vertically. During the process,each template plug is removed from the supporting member it is mated to,after the other template plug has put the next supporting member inplace. The implantation and connection process are detailed below withreference to FIG. 7.

The supporting members 311 of the present invention are configured towork with a working assembly in order to be implanted. The supportingmembers 311 and the working assembly are herein referred to collectivelyas an implantation system 300.

The working assembly matches the supporting members 311 and isconfigured to implant the supporting members 311 into or between asubject's bones. The working assembly includes one or a combination ofdevices selected from the group consisting of an introducer (not shown),a reamer (not shown), a working cannula 33, a tamper (not shown), and atemplate plug 32.

The introducer includes an introducing portion, an extension portion,and a grip portion. The extension portion has one end connected to theintroducing portion and the opposite end connected to the grip portion.The end of the introducing portion that is not connected to theextension portion is pointed and sharp. In one preferred embodiment, theintroducing portion and the extension portion of the introducer may besolid or hollow. The introducer is configured to make a hole into avertebra and gradually enlarge the hole so that the working cannula canbe put into the hole. In fact, the introducer refers to any one of aseries of solid or hollow introducers that have a needle-shapedintroducing portion and vary in size so as to drill and enlarge a holein a vertebra in a successive and gradual manner, lest a large holedrilled into the vertebra in one go injure the surrounding nerves orblood vessels.

The reamer includes a reaming portion, an extension portion, and a gripportion. The extension portion has one end connected to the reamingportion and the opposite end connected to the grip portion. The reamingportion is a sharp spiral structure with which the reamer can move orpull out bone debris. The sharp spiral structure of the reamer can bedriven to a specific position in a bone and ream out bone debris forphysiological examination.

The working cannula 33 includes a hollow tube and a grip portion. Thehollow tube allows insertion by the introducing portion and theextension portion of the introducer, the slender shaft of the tamper,and the two connecting pins and the extension portion of the templateplug 32. The hollow tubular structure of the working cannula 33 not onlycan accommodate the largest of the introducers used to gradually enlargethe hole drilled into a vertebra, but also serves as a passage for thereamer, the tamper, the template plug 32, and the supporting members 311to be implanted, thereby limiting the working position of theimplantation system 300.

Some examples of the tamper and of the template plug 32 will be detailedbelow with reference to embodiments 6 to 8. FIG. 7 shows how thesupporting members 311 are put together using two template plugs 32 andhow the connecting pins 321 of each template plug 32 are mated to theguiding structure of the corresponding supporting member 311. It isfeasible to implant only one supporting member 311 into a bone orbetween two connected bones, or sequentially introduce and connect twoor more supporting members 311 into a bone or between two connectedbones to form a supporting member assembly 31 with adequate supportingstrength.

[Embodiments 6 and 7]—Template Plug

Please refer to FIG. 8 and FIG. 9 for perspective views of two templateplugs 400 according respectively to embodiments 6 and 7 of the presentinvention.

The template plugs 400 according to embodiments 6 and 7 are bothconfigured to guide the supporting member of the present invention intoor between a subject's bones. Each template plug 400 includes aconnecting pin 41, an extension portion 42, and a grip portion 43,wherein the extension portion 42 has one end connected to the connectingpin 41 and the opposite end connected to the grip portion 43.

The connecting pin 41 serves to mate with the guiding structure of asupporting member of the present invention and is therefore configuredto match the guiding structure in, for example, position, structure,and/or number. As stated above, the guiding structure of a supportingmember of the invention may include guiding holes and a buffer groove,both formed in one side of the main body of the supporting member,wherein the number of the guiding holes may be two, three, four, five,etc. It is therefore preferable that there are as many connecting pinsas the guiding holes, i.e., two, three, four, or five connecting pinscorresponding to two, three, four, or five guiding holes respectively.Take embodiments 1 to 4 for example. The supporting member in each ofembodiments 1 to 4 has two guiding holes, and in order to mate with thetwo guiding holes, the template plug 400 in each of embodiments 6 and 7has two connecting pins 41. In embodiment 7, referring to FIG. 9, thetwo connecting pins 41 are connected by a gradually raised buffer base45 that is relatively wide at the rear end and turns pointed toward thefront end, and that is intended to correspond to a gradually deepenedbuffer groove that is relatively wide at a shallow depth and turnspointed as the depth increases. In one preferred embodiment, the twoconnecting pins correspond in design to but are slightly different fromthe intended guiding structure in terms of angle (e.g., diverging orconverging in the forward direction in the same way as the guiding holesof the guiding structure but to a slightly different degree), position(e.g., shifted laterally outward or inward to a small degree withrespect to the guiding holes of the guiding structure), shape (e.g.,being conical or columnar in a slightly different way from the guidingholes of the guiding structure), or size (e.g., tapered in the forwardor rearward direction to a slightly different degree from the guidingholes of the guiding structure). This structural feature, i.e., theslight structural difference between the connecting pins and theintended guiding structure, aims to enable temporary fastening, and thustemporarily prevent separation, between the template plug and eachsupporting member having the intended guiding structure.

To prevent a plurality of template plugs 400 that are used together fromshifting in position during supporting member implantation, eachtemplate plug 400 may further include a coupling and positioningstructure 44, i.e., a third connecting portion 441 and a fourthconnecting portion 442. The third connecting portion 441 is located atan upper side of the extension portion 42 and the grip portion 43, whilethe fourth connecting portion 442 is located at a lower side of theextension portion 42 and the grip portion 43. For example, the thirdconnecting portion 441 is a dovetail projection corresponding to thedovetail recess, or second connecting portion, of a supporting member ofthe present invention and can therefore be pushed into, advanced, andcoupled with the dovetail recess of the supporting member in a slidingmanner, and the fourth connecting portion 442 is a dovetail recesscorresponding to the dovetail projection, or first connecting portion,of the supporting member and can therefore be pushed along, advanced,and coupled with the dovetail projection of the supporting member in asliding manner. As another example, a template plug of the invention mayhave the same upper connecting portion (e.g., dovetail block) and lowerconnecting portion (e.g., dovetail groove) as a supporting member of theinvention so as to connect with another template plug of the sameconfiguration.

Referring to FIG. 9, a “first” (with reference to the order of asequence) template plug 400 has its connecting pins 41 and buffer base45 mated respectively with the guiding holes 141 and the buffer groove142 of a “first” (with reference to the order of a sequence) supportingmember such that the “first” supporting member is held by the “first”template plug 400. After the “first” template plug 400 puts the “first”supporting member securely into a bone or between two connected bones,the third connecting portion 441 of the “first” template plug 400 iscoupled to the dovetail recess, or second connecting portion 13, of a“second” (with reference to the order of a sequence) supporting memberand to the dovetail recess, or fourth connecting portion 442, of the“second” (with reference to the order of a sequence) template plug 400holding the “second” supporting member. When the “second” template plug400 has fastened the dovetail recess, or second connecting portion 13,of the “second” supporting member to the dovetail projection, or firstconnecting portion 12, of the “first” supporting member, the “first”template plug 400 (or more particularly its connecting pins 41 andbuffer base 45) can be removed from the guiding holes 141 and the buffergroove 142 of the “first” supporting member, and by doing so, the thirdconnecting portion 441 of the “first” template plug 400 can also beremoved from the dovetail recess, or fourth connecting portion 442, ofthe “second” template plug 400.

In short, after the “second” template plug holding the “second”supporting member is moved along the “first” template plug and fastensthe “second” supporting member to the “first” supporting member, the“first” template plug can be removed from the “second” template plug. Bythe same token, more than two supporting members can be sequentiallyintroduced into and connected in a bone or between two connected bones.

[Embodiment 8]—Tamper

Please refer to FIG. 10 for perspective views of the tamper 500according to embodiment 8 of the present invention.

The tamper 500 is configured to match the supporting member of thepresent invention and includes a slender shaft 51 and a grip portion 52connected to the slender shaft 51. The tamper 500 serves to restore afractured bone and press down a supporting member that has just beenimplanted.

As shown in the enlarged views of FIG. 10(a) and FIG. 10(b), the tamper500 further includes a coupling and positioning structure 53 so as notto be shifted in position during operation. In this embodiment, thecoupling and positioning structure 53 includes a fifth connectingportion 531 and a sixth connecting portion 532. The fifth connectingportion 531 is located at an upper side of the slender shaft 51 and/orthe grip portion 52 and corresponds in shape to the second connectingportion of the supporting member of the present invention, and the sixthconnecting portion 532 is located at a lower side of the slender shaft51 and/or the grip portion 52 and corresponds in shape to the firstconnecting portion of the supporting member. As the third connectingportion and the fourth connecting portion of the template plug of theinvention also correspond in shape to the second connecting portion andthe first connecting portion of the supporting member of the inventionrespectively, the fifth connecting portion 531 of the tamper 500 canconnect with the fourth connecting portion of the template plug of theinvention in a sliding manner, and the sixth connecting portion 532 ofthe tamper 500 can connect with the third connecting portion of thetemplate plug in a sliding manner. In one preferred embodiment, theconnecting portions of the tamper of the invention have the samestructures as the connecting portions of the supporting member of theinvention (e.g., the upper connecting portion being a dovetail block,and the lower connecting portion being a dovetail groove) in order forthe tamper to connect with the template plug.

The structure of the slender shaft 51 is preferably similar to butflatter than that of the supporting member of the present invention, andthe dimensions of the slender shaft 51 may vary to meet practical needs.In fact, a plurality of tampers 500 whose slender shafts 51 vary in sizemay be used sequentially, in an ascending order of the shaft sizes, toeither gradually push upward the top side of a collapsed fracturedvertebra in order to restore the height of the vertebra, or press down asupporting member that has just been implanted so as to make room forthe next supporting member to be implanted.

Please refer to FIG. 11 to FIG. 14 for schematic drawings showing how animplantation system 600 of the present invention is operated to implanta plurality of supporting members of the invention into a vertebra V orbetween two connected vertebrae V.

As shown in FIG. 11, the operation of implanting a plurality ofsupporting members of the present invention into a vertebra V begins bydrilling a hole into the collapsed fractured vertebra V through one ofits pedicles P and enlarging the hole using a series of introducerswhose sizes are gradually increased. Once the hole is large enough, theworking cannula 63 is placed into the hole, and the reamer is insertedthrough the working cannula 63 to remove the bone debris. Then, thetamper is used to restore the collapsed fractured vertebra V, and asupporting member 611 is subsequently introduced into the vertebra V (orbetween two connected vertebrae V if that is the case) by a templateplug 62. After that, the tamper is used again to restore the collapsedfractured vertebra V and press down the supporting member 611, andanother template plug 62 is used to introduce the next supporting memberinto the vertebra V (or between the two connected vertebrae V), connectthis supporting member to the previous supporting member 611 in asliding manner, and fasten the two supporting members togethervertically.

The present invention allows the supporting member 611 to be implantedinto a subject's bone or between two connected bones, followedsequentially by more supporting members, which are connected to thesupporting member 611 and to one another right in the bone or betweenthe connected bones to form a supporting member assembly 61 (see FIG.12). Depending on the extent of bone fracture and the supportingstrength needed, two supporting member assemblies 61 may be implanted ina bilateral manner (see FIG. 13 and FIG. 14) to overcome such drawbacksof the conventional one-size implants as potential injury to thesurrounding nerves and inadequate support.

In summary of the above, the present invention provides a supportingmember that is configured as a micro-unit and whose small size allowsnot only implantation into a bone or between two connected bones, butalso connection with other such members in the bone or between theconnected bones so as to form a supporting member assembly, makingpossible a minimally invasive, small-incision surgical operation. Inaddition, the invention provides an introducer that can make andgradually enlarge a hole into a bone to enable the placement of aworking cannula into the hole; a reamer for moving or pulling out bonedebris; a tamper for restoring a fractured bone and pushing a previouslyimplanted supporting member; and a template plug that can be used tointroduce a supporting member into a bone or between two connectedbones, connect this supporting member to its immediate predecessor in asliding manner, and fasten the two supporting members togethervertically, before the template plug is removed from the supportingmembers. The invention further provides a supporting member assemblythat is formed by sequentially implanting and connecting a plurality ofsupporting members into a bone or between two connected bones so as topush outward the end plate(s) to be treated and thereby expand thefractured collapsed bone(s). This supporting member assembly is animprovement over the one-size implants used in the conventionalimplantation techniques on the grounds that an existing one-size implantcannot “be a single micro-unit before implantation into or between asubject's bones and connect with other similar micro-units sequentiallyimplanted into or between the bones to form a larger yet completeblock”. Furthermore, unlike the traditional one-size implants, thesupporting member assembly of the invention will not rupture theaffected bone structure (e.g., a pedicle) or injure the surroundingnerves (e.g., the spinal cord or spinal nerves), blood vessels (e.g.,the abdominal aorta or the vertebral arteries), or other importanttissues (e.g., the ureters) during implantation, or provide inadequatesupport due to an expediently smaller-than-required size.

The above is the detailed description of the present invention. However,the above is merely the preferred embodiment of the present inventionand cannot be the limitation to the implement scope of the presentinvention, which means the variation and modification according to thepresent invention may still fall into the scope of the invention.

What is claimed is:
 1. A supporting member for implantation into orbetween a subject's bones, comprising: a main body having two oppositesides defined respectively as an upper side and a lower side; a firstconnecting portion formed at the upper side of the main body and shapedas a male or female part of a dovetail joint; a second connectingportion formed at the lower side of the main body and corresponding inshape to the first connecting portion; and a guiding structure formed ata side of the main body and configured to mate with an external templateplug; wherein the first connecting portion of the supporting member isconnectable with the second connecting portion of another saidsupporting member to form a said dovetail joint.
 2. The supportingmember of claim 1, wherein the first connecting portion is a dovetailblock and the second connecting portion is a dovetail groove in order toprevent two vertically connected said supporting members from separatingfrom each other after connecting in a sliding manner.
 3. The supportingmember of claim 2, wherein a front side of the first connecting portionfurther includes a first positioning portion, a front side of the secondconnecting portion further includes a second positioning portion, andthe second positioning portion corresponds in shape and position to thefirst positioning portion; wherein, the first positioning portion is apositioning block and the second positioning portion is a positioninghole so that the supporting members with such structures are able toposition and fasten to each other.
 4. The supporting member of claim 1,wherein a front side of the main body has a U-shaped groove structurethat can be compressed or deformed to facilitate fastening betweensupporting members and return to an original shape elastically toprevent the supporting members from separating from each other.
 5. Thesupporting member of claim 1, wherein the guiding structure includes aplurality of guiding holes and/or buffer grooves.
 6. The supportingmember of claim 5, wherein the guiding holes and the buffer grooves havevarious designs with progressive deviation or difference in terms ofangle, position, size, or shape.
 7. The supporting member of claim 1,wherein the main body is one or a plurality of reticulated structures.8. The supporting member of claim 7, wherein the reticulated structurecan be filled with a bone-filling material or bone cement.
 9. Thesupporting member of claim 1, wherein the bone is a vertebra.
 10. Thesupporting member of claim 1, wherein a material of the supportingmember includes metal, plastic, or a mixture thereof.
 11. A templateplug configured to guide the supporting member of claim 1 into orbetween a subject's bones, which includes a plurality of connectingpins, an extension portion, and a grip portion, wherein the extensionportion has one end connected to the plural connecting pins and anopposite end connected to the grip portion, and the extension portionand/or the grip portion has: a third connecting portion, which is formedon an upper side of the extension portion and/or the grip portion, andis a dovetail projection; a fourth connecting portion, which is formedon a lower side of the extension portion and/or the grip portion, andcorresponds to the third connecting portion; wherein, the pluralconnecting pins can be correspondingly engaged with the guidingstructure of the supporting member.
 12. The template plug of claim 11,wherein the template plug further includes a plurality of connectingpins and buffer bases.
 13. The template plug of claim 12, wherein thetemplate plug has two connecting pins that correspond in design to butare slightly different from the guiding structure in terms of angle,position, shape, or size.
 14. The template plug of claim 11, wherein thethird connecting portion of the template plug can correspond to thesecond connecting portion of the supporting member and the fourthconnecting portion can correspond to the first connecting portion of thesupporting member so that the template plug can be pushed along andcoupled with the supporting member in a sliding manner.
 15. A tamper,which can correspondingly match the supporting member of claim 1 or thetemplate plug of claim 11, the tamper includes a slender shaft and agrip portion connected to the slender shaft; wherein, an upper side ofthe slender shaft and/or the grip portion further includes a fifthconnecting portion corresponding to the second connecting portion, and alower side of the slender shaft and/or the grip portion further includesa sixth connecting portion corresponding to the first connectingportion.
 16. A supporting member assembly to be implanted into orbetween a subject's bones, which includes a plurality of supportingmembers of claim 1, wherein the first connecting portion of eachsupporting member forms a dovetail joint with the second connectingportion of another said supporting member in order to connect the pluralsupporting members sequentially.